Another pose in which my quads sabotage me!
There's a lot going on in Navasana. To hold the v-sit you have hold the weight of your torso and legs. The hip flexors connected to the low back and thighs are all working together here to hold you up and balance. So the abs and back muscles are working together here in sort of an opposition in order to keep a super straight spine. For me this is not happening and I have to bend my knees and kept them parallel to the floor instead of having legs extended. With tight hamstrings such as mine, there will be no straightening of the knees!